If you can .... do both
SuperDuper! or Carbon Copy Cloner make a bootable snapshot of your machine at a given moment in time.
Time Machine complements this by taking a copy of modified files every hour ( by default ) so you can have multiple copies of the same file on a TM backup and you can travel back in time to find the correct version of a file.
Also TM can work completely unattended with a Time Capsule, whilst you have to explicitly launch SuperDuper! or CCC so TM is very convenient to have.
However, if you need to do a complete system restore, your CCC bootable backup will be the quickest solution.
There are different backup strategies and my suggestion is to take a step back and decide what you want to protect yourself against, how quickly you want to be back in business again after a failure and how much effort you are willing to invest to re-create lost or corrupted data.
Once you have this figured out, then technology can step in and do the work for you.;D
Cheers ... McBie